I’m cutting aluminum parts (same parts, same bit, same settings as parts I cut about two weeks ago). I’d get partway through the cut and the machine would start chattering. I stopped to inspect it and the Z-axis plate was very loose - the guide wheel hardware had loosened, so the guide wheels had lost contact. The first time, I took it all apart, threadlocked the guide wheel hardware, put it back together & adjusted everything properly. It cut well for a while, then it happened again. I tightened the hardware again & was able to finish the parts.
What could be happening? I don’t know if the chattering is causing the hardware to loosen, or if the loosening hardware is causing the chattering. Maybe it gets started with minor chattering & vibration, then ‘takes off’ as the wheels lose contact & gets much worse.
I’d suspect exactly what you’re described more/less.
You could go through the effort of loctite again (let 24 hrs cure before any use).
It could be a fairly aggressive toolpath with a now dull bit is taking extra effort - not cutting as clean as once was. 10x loupe or similar to inspect endmill edge. Harmonics and vibration will loosen up hardware so if you can reduce it then you’ll be saving yourself grief all over the machine.
Any of the linear Z axis upgrades is an exceptional improvement for alloy. I really recommend doing so to stiffen up the machine and produce better parts.
If part of your problem is the eccentric nuts Luke (Mr. Beaver) had a great upgrade nut set. Also locktite is not instant. It needs time to dry I suggest 262 or 263 (blue) Locktite
Thanks. I’m definitely planning on a Z axis upgrade, just not yet.
I had marked a line across the eccentric nut & screw with a sharpie. The screw isn’t turning on the nut - i think the whole assembly is losing its ‘grip’ on the plate & spinning. Maybe it’s wearing down or polishing the bearing surface, making it easier to spin. it might help if I could get some sort of lockwasher in there.